Apparatus for closing a filled, flanged carton tray

ABSTRACT

A method and apparatus for sealing a filled, flanged carton tray with a flat lid. The tray is advanced into a sealing machine while resting on a conveyor (3) and at random spacing between trays. At a predetermined position the tray has a lid (2) placed on it, the lid (2) engaging against a stop curtain (4) and awaiting the tray (1), this being the lid (2) which is to be sealed against the flanges of the tray. The tray with the lid on it is then advanced by rollers (5-8) into a first microwave applicator (11), which includes longitudinal rails (12, 13) with a C-shaped cross section, for sealing a pair of opposing lid edge portions against respective flanges of the tray (1), subsequent to which, compression or sealing rollers (14-17) situated in the advancing direction of the conveyor press against the lid (2), which was sealed immediately previously, and before the tray (1) is turned 90° horizontally for sealing in a second microwave applicator (19) the remaining, opposing parts of the lid (2) against the respective flanges on the tray (1).

The present invention relates to a method and apparatus for closing afilled, flanged carton tray with the aid of a flat lid.

The machines used today for sealing such packs have been found to beboth expensive in manufacture and operation as well as in maintenance.

The object of the present invention is to provide a machine which ischeap to produce and to operate, with the aid of which a filled tray canbe sealed very efficiently.

SUMMARY OF THE INVENTION

The present invention relates to a method and apparatus for sealing lidsonto cartons, the apparatus including: conveying means for conveying thecartons without regard to the spacing between the cartons; lid applyingmeans for applying the lids onto the cartons; heat generating means forgenerating heat to fix the lids to the cartons; pressing means forsubsequently pressing the lids against the cartons; turning means forsubsequently turning the cartons; and further fixing means forsubsequently further fixing the lids to the cartons.

Preferably, the conveying means includes a belt conveyor. Preferably,the belt conveyor includes a short feed section for conveying thecartons toward the lid applying means, the conveying means including asecond belt conveyor for conveying the cartons from the lid applyingmeans.

Preferably, the lid applying means includes moving means for moving thelids to a lid applying position above the conveying means. Preferably,the lid applying means includes stopping means for stopping each of thelids until a respective one of the cartons is located below the lidapplying position. Preferably, the apparatus includes transferring meansfor transferring the lids and the cartons to the heat generating means.Preferably, the stopping means is actuated by the cartons to release thelids from the stopping means. Preferably, the stopping means includes astop curtain. Preferably, the moving means includes rails. Preferably,the transferring means includes rollers.

Preferably, the heating means includes a microwave applicator.Preferably, the microwave applicator includes rails, the rails beingC-shaped so as to accommodate the lids and the cartons.

Preferably, the pressing means includes rollers.

Preferably, the turning means includes means for horizontally rotatingthe cartons through 90°.

Preferably, the further fixing means includes a microwave applicator.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail below with referenceto the accompanying drawings, on which

FIG. 1 is a schematic plan of a sealing machine in accordance with thepresent invention,

FIG. 2 is a schematic perspective view of a part of the machineillustrated in FIG. 1, this part being at the approach end of themachine seen in the advancing direction of the tray,

FIG. 3 is a schematic side view of the approach part seen in thedirection of tray advance of the machine illustrated in FIG. 1, and alsoshows the part of the machine illustrated in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The machine illustrated on the drawings has at least one conveying means3 passing through it for advancing and simultaneously sealing flangedtrays 1, which have been filled somewhere else. The trays 1 are advancedwith no particular spacing on the conveyor means 3 and come into theforward part of the machine, seen in the advancing direction of thetrays 1, and up to a position in front of a stop curtain 4, againstwhich a lid 2 is already lying in wait for the tray 1 it is to seal. Thelid 2 is supplied from a magazine 20 situated above the conveyor means3, and is supported in position above the carton by longitudinal rails9, 10 situated along and above the means 3 and the trays 1 on said means3. When the lid 2 is situated directly above a tray 1 below it, both aresimultaneously advanced by rollers 5, 6, 7, 8 situated on either side ofthe means 3. Tray and lid are advanced together to a first microwaveapplicator 11, which includes C-shaped rails 12, 13 on either side ofthe conveyor means 3. The flanges of the tray and the sealing edges ofthe lid are accommodated in the gaps of the rails 12, 13 and sealedtogether with the aid of microwaves. After the applicator 11 there arepressure rollers 14, 15, 16, 17 intended to press the sealed flange andlid parts together before the tray 1 is advanced to a turntable means18, where the tray 2 is turned horizontally through an angle of 9O° toenable sealing the remaining flanges of the tray 1 to the lid or viceversa, with the aid of a second microwave applicator 19, which issituated after the turntable means 18 but before a discharge part of themachine. The second microwave applicator 19 is formed similar to thefirst one, and operates in the same way. In the illustrated embodiment,the conveyor means 3 is made up from standard belt conveyors, andcomprises two sections, a short feed section and a section for remainingsteps in the machine. A rotary principle is used for transferring thelids from the magazine 20. Setting-up for different tray sizes can bedone manually within a period of 30 minutes.

I claim:
 1. An apparatus for sealing a flat lid onto a carton tray, theflat lid having first and second pairs of opposing sides, the cartontray being filled, the carton tray having first and second pairs ofopposing flanges, the opposing sides of the flat lid corresponding tothe opposing flanges of the carton tray, said apparatus comprising:aconveyor for conveying the carton tray through said apparatus withoutregard to the position of the carton tray with respect to other cartontrays; rails for supporting the flat lid above said conveyor; a stopcurtain for maintaining the flat lid against said rails until the cartontray is located beneath the flat lid; a microwave applicator for fixingthe first pair of opposing sides to the first pair of flanges, saidmicrowave applicator including rails, said rails of said microwaveapplicator being C-shaped so as to accommodate the first pair of sidesand the first pair of flanges during fixing of the first pair of sidesto the first pair of flanges; advancing rollers for advancing the cartontray and the flat lid toward the microwave applicator, said advancingrollers being located close to said stop curtain; pressure of sealingrollers for subsequently pressing down on the flat lid; turning meansfor subsequently horizontally turning the carton tray through 90°; and asecond microwave applicator for subsequently sealing the second pair offlanges to the flat lid.
 2. An apparatus for sealing lids onto cartons,said apparatus comprising:conveying means for conveying the cartonswithout regard to the spacing between the cartons; lid applying meansfor applying the lids onto the cartons; heat generating means forgenerating heat to fix the lids to the cartons; pressing means forsubsequently pressing the lids against the cartons; turning means forsubsequently turning the cartons; and further fixing means forsubsequently further fixing the lids to the cartons; wherein said lidapplying means includes moving means for moving the lids to a lidapplying position above said conveying means; wherein said lid applyingmeans includes stopping means for stopping each of the lids until arespective one of the cartons is located below the lid applyingposition.
 3. The apparatus of claim 2, wherein said conveying meansincludes a belt conveyor.
 4. The apparatus of claim 3, wherein said beltconveyor includes a short feed section for conveying the cartons towardsaid lid applying means, said conveying means including a second beltconveyor for conveying the cartons from said lid applying means.
 5. Theapparatus of claim 2, wherein said apparatus includes transferring meansfor transferring the lids and the cartons to said heat generating means.6. The apparatus of claim 5, wherein said stopping means is actuated bythe cartons to release the lids from said stopping means.
 7. Theapparatus of claim 6, wherein said stopping means includes a stopcurtain.
 8. The apparatus of claim 7, wherein said moving means includesrails.
 9. The apparatus of claim 8, wherein said transferring meansincludes rollers.
 10. The apparatus of claim 2, wherein said heatgenerating means includes a microwave applicator.
 11. The apparatus ofclaim 10, wherein said microwave applicator includes rails, said railsbeing C-shaped so as to accommodate the lids and the cartons.
 12. Theapparatus of claim 2, wherein said pressing means includes rollers. 13.The apparatus of claim 2, wherein said turning means includes means forhorizontally rotating the cartons through 90°.
 14. The apparatus ofclaim 2, wherein said further fixing means includes a microwaveapplicator.